1. Field of the Invention
This invention is in the field of bird feeders, and more particularly related to the type of bird feeder having a main hollow housing with vertically staggered feeding apertures cut therethrough.
2. Description of the Prior Art
A wide variety of bird feeders has been developed, including many which supply a number of feeding apertures from a central supply of feed. A representative sampling which are described in the patent literature includes the following.
Klix, in U.S. Pat. No. 2,683,440, discloses a bird feeder having a relatively large supply of bird feed provided for three feeding apertures. The Klix feeder has a hopper section, preferably made from transparent material, with a cylindrical shape at its top portion and a frustro-conical shape at its lower portion. The lower portion is designed so that a bird which is feeding must lower its head to pick feed from the central supply and subsequently step back before raising its head to crack the feed shell. The design is intended to insure that feed shells are dropped outside of the feeder instead of into the central supply of feed.
Another bird feeder having a relatively large supply of feed provided for a plurality of feeding apertures is taught by Boehland in U.S. Pat. No. 3,788,279. The Boehland feeder is formed from a hollow globe having a funnel mounted within it to divide the glove into an upper storage area and a lower feeding chamber. An orifice in the lower end of the funnel provides a flow of feed from the storage area to a plurality of ports located on the side of the lower hemispherical section.
Bird feeders of the type disclosed by Klix and Boehland do provide more than one aperture so that a number of birds can feed at one time. Nevertheless, their basic construction involves the concept of havng a main supply of bird feed located in the upper portion of a feeder whereas all of the feeding apertures are located at the bottom. This design restricts the number of feeding apertures possible, and therefore, the number of birds which can feed. In both of these feeders, as well as other feeders of this type, the number of feeding apertures which can be built into the feeder is restricted to the number which can be positioned around the circumference of the feeders at the same height.
To overcome this restriction, bird feeders have been proposed wherein feeding apertures are vertically staggered as well as horizontally staggered. One of these is disclosed by Mayes in U.S. Pat. No. 2,634,705. The Mayes bird feeder is a knock-down type formed from a series of wooden slats inserted into slots in the sidewalls of the feeder to form a plurality of feeding locations. Each feeding location is supplied with bird feed from a main supply in the central portion of the feeder.
Another design, and one of the more popular bird feeders, is that described by Kilham in U.S. Pat. No. 3,568,641. The Kilham bird feeder has a vertically disposed hollow tubular housing with a series of staggered openings through its sidewall which serve as feeding apertures. The specific designed feature stated to be novel is a baffle means provided within the main housing adjacent to feeding apertures. This baffle is generally arcuate in cross-section and extends substantially more than 180.degree.. It serves to insure that feed will gravitate around the aperture to form a level of bird feed automatically at each baffle. Thus, when a bird inserts its head through a feeding aperture, it has free access to bird feed located beneath the baffle. As feed is eaten or agitated, the main supply automatically moves downwardly to maintain the feed level constant until the level of feed in the tubular housing drops below a particular aperture.
Although the Kilham bird feeder has proven to be very successful, it does have at least one serious drawback. Namely, as feed is depleted in the main tubular housing, it eventually drops below the higher feeding apertures. Thus, these apertures become inoperative since they no longer have a supply of feed. Because of this, the number of feeding apertures which are operative is directly related to the level of feed in the tubular housing. Thus, as feed is depleted, and the level drops, the advantage of providing a plurality of vertically staggered apertures is partially or totally offset. The higher feeding apertures can only be resupplied with feed by introducing a new supply of feed into the main housing, and it is not always convenient to do so each time the level of feed drops to a level lower than the higher feeding apertures.